Evaluating the specificity of a new type of urine collection bag for infants.
OBJECTIVE
For diagnosing urinary tract infection (UTI) in infants, the urine collection bag is a common sampling method. It has several advantages versus other methods but a high risk of contamination makes culture results difficult to evaluate. Previous studies report a specificity ranging from 14% to 84%. The objective of this study was to evaluate the specificity of a new type of urine collection bag.


METHODS
Urine samples were collected from healthy infants with a new type of collection bag. As the urine is expected to be sterile, any bacterial growth would be considered a contamination.


RESULTS
Forty-four samples were included: 40 samples showed <10,000 cfu/ml of mixed growth or no growth at all, three samples showed <10,000 cfu/ml of single-strain growth and one sample showed >10,000<100,000 cfu/ml of single-strain growth. No samples showed any growth >100,000 cfu/ml.


CONCLUSIONS
According to Kass criteria, 97.7% of the samples would exclude a UTI and 2.3% would be considered inconclusive. None of the samples had a contamination level that, falsely, would be interpreted as positive. Further studies will be valuable as a specificity of 97.7% suggests that this collection device could give the clinician a non-invasive option for diagnosing UTI in infants.
Perlhagen
Markus
M
Department of Pediatrics, Hospital of Helsingborg, Lindahls v. 9, 260 83 Vejbystrand, Sweden.
Forsberg
Thomas
T
Perlhagen
John
J
Nivesjö
Michael
M